1. Field of the Invention
This invention relates to an apparatus and method for treating water with ozone, particularly for drinking water and ice making.
2. Description of Related Art
It has been well known for many years that water can be purified of harmful organisms by treating it with ozone. However, there is a problem in trying to dissolve ozone in the water to purify it and yet not discharge a significant portion of unreacted ozone from the water, thus wasting it and potentially creating a health hazard.
Four types of gas-liquid contactors have been used for this purpose including spray towers, where liquid is dispersed in a gas, packed beds, bubble plates or sieve towers, and finally units for dispersing gas bubbles in a liquid.
Many of the apparatuses have been designed for industrial purposes, but are not well adapted for use where a relatively compact unit is required for the continuous production of purified water, such as in association with an in-store ice maker or an in-home water purifier.
The use of loop reactors for processes involving liquids and gases has been suggested in such earlier references as U.S. Pat. No. 3,562,349 to Pawloski. In this reference, a pump circulates liquid about a closed loop with inlets and outlets including a gas outlet at the top of the unit.
U.S. Pat. No. 4,252,654 to Leitzke relates specifically to treating water with ozone. Here the water circulated about the loop is split into separate paths for treatment. Only a portion of the total flow of water is treated with ozone by one pass only about the loop. A packed column is employed with a portion of the water sprayed from the top.
Another apparatus for treating water with ozone by circulating it about a loop is shown in U.S. Pat. No. 3,945,918 to Kirk. There is a turbulent zone for mixing the water with ozone as well the setting up of a counterflow of ozone through the water.
However, none of these earlier devices or processes has yielded an efficient, compact apparatus or a process which has gained wide acceptance for purposes such as treating water for ice making or in-home water purification.